The process of the present invention solves the problem of removal of inorganic nitrite ions from aqueous solutions which result from the manufacture or disposal of nitrocellulose or other nitrate ester. The problem is brought about where there is chemical or enzymatic denitration of a nitrate ester resulting in the release of nitrite ions to an aqueous solution.
The disposal of nitrocellulose scrap has been dealt with in the past by burning the scrap in air, or by alkaline hydrolysis of the scrap followed by microbial utilization of the degradation products. Burning results in air pollution, and as a result is illegal in a great many locations. There are other procedures which have been described to modify nitrocellulose by removal of the nitrate ester group. These procedures include the application of inorganic sulfides or the treatment of the nitrocellulose polymer with inorganic hydrides.
In the process where digestion of the nitrocellulose particulate is accomplished with alkali, it is followed by two microbiological procedures. The process of the present invention described here has the advantage over that earlier one of greater control over the denitrification process. This is accomplished by the substitution of enzymes for potentially variable microbial populations.